This invention relates to correction fluids.
Correction fluids are used for correcting handwritten, typewritten or photocopied markings on paper. Generally, correction fluids are applied to a paper surface in liquid form. After application, the fluids dry relatively quickly to provide a film which can effectively cover erroneous markings on the surface and can receive a corrected marking. It is desired that the dried film be strongly bonded to the paper surface, and sufficiently flexible that the film will not be removed under normal conditions. It is also desired that the composition dry at a rapid rate. Other desired performance characteristics include good storage stability, and flow and viscosity characteristics which permit easy and even application of the fluid.
Correction fluids typically contain a binding resin that provides the flexible film, and an opacifying pigment, usually titanium dioxide, dispersed in a solvent. It is desirable, for environmental reasons, that correction fluids include little or no volatile organic solvents.
Correction fluids are often supplied in a small bottle with an applicator brush attached to the cap. Since the opacifying pigment in the fluid (typically titanium dioxide) tends to settle out over time, glass or metal mixing beads are sometimes included to help redisperse the agent, the user being instructed to shake the bottle prior to use. However, thorough shaking is commonly regarded as a nuisance, so that much of the opacifying pigment remains at the bottom of the bottle. This condition is exacerbated by evaporation of the solvent component when the bottle is open. Accordingly, much of the correction fluid in each bottle may be thrown away as the solids become increasingly difficult to redisperse.